非配对设计多值名义资料一水平多重Logistic回归分析

本文目的是介绍非配对设计多值名义资料一水平多重logistic回归分析的基本原理、建模策略及注意事项。结合实例,应用SAS 9.4构建未经变量筛选和经变量筛选的多值名义资料多重logistic回归模型。通过回归分析的计算结果可知,同一变量的回归系数在不同logit函数中存在代数关系。多值名义多重logistic回归分析可以用来处理结果变量为多值名义变量的回归建模问题,并可以结合SAS实现对自变量的筛选,以获得简洁的回归模型。     

非配对设计二值资料多水平多重Logistic回归分析

本文目的是介绍非配对设计二值资料多水平多重logistic回归模型的构建与求解方法。首先介绍模型的有关概念及模型的构建原理,基于实例使用SAS软件对列联表资料进行分析,以proc glimmix和proc nlmixed过程构建和求解模型,并对相关结果进行解释和比较。     

非配对设计多值有序资料一水平多重Logistic回归分析

本文目的是介绍非配对设计多值有序资料一水平多重logistic回归模型的构建与求解方法。本文详细介绍了构建累积logistic回归模型的原理和具体方法,并结合实例介绍如何使用SAS软件中的LOGISTIC过程来拟合此回归模型,并对逐步回归法的输出结果进行了解释;其次讨论了有关构建累积logistic回归模型的过程中自变量筛选、模型评价以及拟合模型时需注意的问题。     

复杂抽样调查设计多值名义资料一水平多重Logistic回归分析

本文目的是介绍复杂抽样调查设计多值名义资料一水平多重logistic回归模型构建，并探讨不同策略之间的差异。采用SAS中的LOGISTIC过程和SURVEYLOGISTIC过程，分别按照是否考虑抽样设计与是否考虑抽样权重共4种分析策略对数据构建广义logistic回归模型，并比较结果。不同分析策略所得结果显示，不仅参数估计值、回归系数标准误、OR值及其置信区间的估计值有所差别，而且对纳入模型的解释变量也有影响。因此，在对复杂抽样调查设计多值名义资料构建广义logistics回归模型时，既要考虑抽样设计，又要兼顾抽样权重，否则即使样本量足够大，也会导致错误的推断结论。     

非配对设计多值有序资料多水平多重Logistic回归分析

本文目的是介绍多值有序资料多水平多重logistic回归分析方法。此法是在层次结构数据的基础上，构建多值有序因变量随一组自变量变化而变化的回归模型。具体的做法如下：①先介绍有关的基本概念；②呈现待分析的数据结构；③扼要介绍回归模型的构建与求解；④详细介绍如何使用SAS的GLIMMIX和NLMIXED两个过程来拟合此回归模型，并对相关结果进行解释和比较；⑤讨论多水平结构数据下拟合累积logistic回归模型时需注意的问题。     

合理进行多重Logistic回归分析——结合多水平模型分析

本文目的是介绍如何结合多水平模型分析,合理地进行多重Logistic回归分析的方法。第一,介绍了与多水平模型分析有关的4个基本概念。第二,介绍了构建多水平模型的3个步骤。第三,通过一个多中心药物临床试验的实例,介绍了如何用SAS软件进行分析的全过程,其内容如下：①检验各中心优势比之间是否具有齐性;②对试验中心产生哑变量后构建多重Logistic回归模型;③将试验中心视为分层变量构建多重Logistic回归模型;④构建随机截距多水平多重Logistic回归模型;⑤构建随机截距和随机斜率多水平多重Logistic回归模型。得到的结论是,当具有二值结果变量的各层级资料间存在差异时,最合适的做法是构建多水平多重Logistic回归模型。     

非配对设计二值资料一水平多重Logistic回归分析

本文的目的是介绍非配对设计二值资料一水平多重Logistic回归模型的构建与求解方法。基于SAS软件分别对以列联表和数据库形式呈现的定性资料进行全面分析,并得出了4个对提高模型拟合优度很有价值的结论:第一,若资料以列联表形式呈现,应拟合"加权"Logistic回归模型;第二,若资料中包含定量自变量,不适合将其定性化;第三,若资料中包含定量自变量,应依据定量自变量和二值自变量产生出派生自变量;第四,若资料中有定性自变量时,必须将多值名义或有序自变量进行哑变量变换,不需要依据二值自变量产生出派生自变量。     

1∶r配对设计二值资料一水平多重Logistic回归分析

本文的目的是介绍"1∶1""1∶2"和"1∶r"配对设计二值资料一水平多重Logistic回归分析方法。统计分析的前提条件是资料值得分析,而确保配对设计二值资料值得分析的重要基础是"配对设计"科学合理。为此,本文从六个方面阐述"配对设计的要领",不仅介绍了构建"1∶1""1∶2"和"1∶r"配对设计二值资料一水平多重Logistic回归模型的方法,还通过三个实例,介绍了采用SAS软件实现统计分析及结果解释的详细步骤。     

复杂抽样调查设计多值有序资料一水平多重Logistic回归分析

本文目的是比较不同分析策略对复杂抽样调查设计多值有序资料一水平多重logistic回归分析结果的异同。通过实例分析,利用四种不同的分析策略(将复杂抽样视为单纯随机抽样,考虑抽样设计不考虑抽样权重,考虑抽样权重不考虑抽样设计,同时考虑抽样设计和抽样权重)对复杂抽样设计多值有序资料进行建模。在四种不同分析策略的累积logistic回归模型拟合的结果中,自变量的偏回归系数、标准误差及P值均有所不同。在对复杂抽样调查设计的多值有序资料回归建模时,将抽样设计和抽样权重纳入统计分析,会得到更准确、更稳健的分析结果。     

如何正确运用χ~2检验——高维表资料统计分析方法概述

本文目的是介绍高维表资料的种类及其对应的统计分析方法。基于结果变量的资料类型,常见的高维表资料可分为以下三类,即结果变量为二值变量、多值名义变量和多值有序变量。高维表资料的统计分析方法主要有两大类,第一类为广义差异性分析,内容包括"加权χ~2检验""CMH χ~2检验"和"Meta分析";第二类为回归分析,内容包括"对数线性回归模型分析""Logistic回归模型分析""Probit回归模型分析"和"离散选择模型分析"。     

Development of the projection from the nucleus of the brachium of the inferior colliculus to the superior colliculus in the ferret

Neurons in the deeper layers of the superior colliculus (SC) have spatially tuned receptive fields that are arranged to form a map of auditory space. The spatial tuning of these neurons emerges gradually in an experience-dependent manner after the onset of hearing, but the relative contributions of peripheral and central factors in this process of maturation are unknown. We have studied the postnatal development of the projection to the ferret SC from the nucleus of the brachium of the inferior colliculus (nBIC), its main source of auditory input, to determine whether the emergence of auditory map topography can be attributed to anatomical rewiring of this projection. The pattern of retrograde labeling produced by injections of fluorescent microspheres in the SC on postnatal day (P) 0 and just after the age of hearing onset (P29), showed that the nBIC-SC projection is topographically organized in the rostrocaudal axis, along which sound azimuth is represented, from birth. Injections of biotinylated dextran amine-fluorescein into the nBIC at different ages (P30, 60, and 90) labeled axons with numerous terminals and en passant boutons throughout the deeper layers of the SC. This labeling covered the entire mediolateral extent of the SC, but, in keeping with the pattern of retrograde labeling following microsphere injections in the SC, was more restricted rostrocaudally. No systematic changes were observed with age. The stability of the nBIC-SC projection over this period suggests that developmental changes in auditory spatial tuning involve other processes, rather than a gross refinement of the projection from the nBIC.     

The organization of the connections between the cortex and the claustrum in the monkey

The distribution of labelled cells and of extracellular granules in the claustrum has been studied after injections of horseradish peroxidase in several areas of the neocortex. The frontal and parietal lobes are related to the anterior and posterior halves respectively of the claustrum, and the occipital and temporal cortex to the posterior and inferior margins. Parts of the claustrum related to areas of the cortex in the frontal lobe overlap considerably in the antero-posterior dimension with parts related to widely separated but interconnected areas of the parieto-temporal cortex. Areas of cortex within one lobe which are interconnected are related to parts of the claustrum which overlap in the dorsoventral dimension.     

Sexual pheromones and the evolution of the reward system of the brain: the chemosensory function of the amygdala

The amygdala of all tetrapod vertebrates receives direct projections from the main and accessory olfactory bulbs, and the strong similarities in the organization of these projections suggest that they have undergone a very conservative evolution. However, current ideas about the function of the amygdala do not pay sufficient attention to its chemosensory role, but only view it as the core of the emotional brain. In this study, we propose that both roles of the amygdala are intimately linked since the amygdala is actually involved in mediating emotional responses to chemical signals. The amygdala is the only structure in the brain receiving pheromonal information directly from the accessory olfactory bulbs and we have shown in mice that males emit sexual pheromones that are innately attractive for females. In fact, sexual pheromones can be used as unconditioned stimuli to induce a conditioned attraction to previously neutral odorants as well as a conditioned place preference. Therefore, sexual pheromones should be regarded as natural reinforcers. Behavioural and pharmacological studies (reviewed here) have shown that the females' innate preference for sexual pheromones is not affected by lesions of the dopaminergic cells of the ventral tegmental area, and that the systemic administration of dopamine antagonists do not alter neither the attraction nor the reinforcing effects of these pheromones. Anatomical studies have shown that the vomeronasal amygdala gives rise to important projections to the olfactory tubercle and the islands of Calleja, suggesting that these amygdalo-striatal pathways might be involved in the reinforcing value of sexual pheromones.     

A projection to the striatum from the medial subdivision of the posterior group of the thalamus in the cat

Injections of wheat germ agglutinin-conjugated horseradish peroxidase in the lateral part of the caudate nucleus or the putamen of the cat result in retrograde thalamic cell-labeling in the rostral extension of the medial subdivision of the posterior group (POM). Autoradiography after [³H]amino acid injection of POM reveals a dense and discontinuous distribution of axons in the lateral half of the caudate and putamen concentrated at their middle rostrocaudal levels. This newly discovered thalamostriatal projection of POM may account for somatosensory activity observed in striatal cells.     

Role of the paraventricular nucleus in the projection from the nucleus of the solitary tract to the olfactory bulb

Electrophysiological experiments were performed on anesthetized rats to determine the effects of lesions of the paraventricular nucleus on the amplitude of evoked potentials recorded in the periglomerular layer of the olfactory bulb after nucleus of the solitary tract electrical stimulation. Lesions of the paraventricular nucleus enhance the amplitude of both the positive and negative components of the evoked potential in the olfactory bulb. The pathway from the paraventricular nucleus to the olfactory bulb seems to exert a suppressive influence over the projection from the nucleus of the solitary tract to the olfactory bulb under these conditions.     

Evidence for the collateral innervation of the esophagus and the heart from neurons in the compact formation of the nucleus ambiguus of the rat

We investigated whether the heart receives collateral projections from the neurons which innervate the esophagus with a retrograde double-labeling method using two fluorescent tracers. Following injections of True Blue (TB) into the esophagus and Diamidino Yellow (DY) into the heart, about 21.9% of the labeled esophageal motoneurons in the compact formation of the nucleus ambiguus (AmC) were retrogradely double labeled. No single-labeled cardiac motoneurons were found in the AmC. The present results provide anatomical substrates for the esophagocardiac reflex.     

Projections from the five divisions of the orbital cortex to the thalamus in the rat

The orbital cortex (ORB) of the rat consists of five divisions: the medial (MO), ventral (VO), ventrolateral (VLO), lateral (LO), and dorsolateral (DLO) orbital cortices. No previous report has comprehensively examined and compared projections from each division of the ORB to the thalamus. Using the anterograde anatomical tracer, Phaseolus vulgaris leucoagglutinin, we describe the efferent projections from the five divisions of the ORB to the thalamus in the rat. We demonstrated that, with some overlap, each division of the ORB distributed in a distinct (and unique) manner to nuclei of the thalamus. Overall, ORB projected to a relatively restricted number of sites in the thalamus, and strikingly distributed entirely to structures of the medial/midline thalamus, while completely avoiding lateral regions or principal nuclei of the thalamus. The main termination sites in the thalamus were the paratenial nucleus (PT) and nucleus reuniens (RE) of the midline thalamus, the medial (MDm) and central (MDc) divisions of the mediodorsal nucleus, the intermediodorsal nucleus, the central lateral, paracentral, and central medial nuclei of the rostral intralaminar complex and the submedial nucleus (SM). With some exceptions, medial divisions of the ORB (MO, VO) mainly targeted “limbic-associated” nuclei such as PT, RE, and MDm, whereas lateral division (VLO, LO, DLO) primarily distributed to “sensorimotor-associated” nuclei including MDc, SM, and the rostral intralaminar complex. As discussed herein, the medial/midline thalamus may represent an important link (or bridge) between the orbital cortex and the hippocampus and between the ORB and medial prefrontal cortex. In summary, the present results demonstrate that each division of the orbital cortex projects in a distinct manner to nuclei of the thalamus which suggests unique functions for each division of the orbital cortex.     

On the origin of the serotonergic input to the intermediate lobe of the rat pituitary

Single stimulations of the vagina and cervix were performed between proestrus and the first day of diestrus with a stimulator designed to grade the intravaginal penetration of a rod. The percent incidence of pseudopregnancy after this stimulation was exponentially related to the extent of intravaginal penetration and was also affected by the stage of the cycle at which the stimulation was performed. At 10.00 h on proestrus, an exponential increase in the incidence of pseudopregnancy was observed with shallow penetrations, while an exponential decrease was found when deeper penetrations were applied. Such negative exponential correlation had disappeared at 22.00 h on proestrus. At that time, also, some responses were elicited by very shallow penetrations (17 mm) and all the animals responded to penetrations of 20 mm or more. Sensitivity to cervicovaginal stimulation at 10.00 h on estrus was lower than that at 22.00 h on proestrus and it was even lower at 10.00 h on the first day of diestrus. The response to 18 mm of penetration was studied every 3 h between 10.00 h on proestrus and 10.00 h on estrus, and then every 12 h until 10.00 h on the first day of diestrus. This stimulation was usually ineffective to induce pseudopregnancy, except for a brief period encompassing the night between proestrus and estrus, when a peak in the incidence of responses was reached. This peak sensitivity could be advanced following the s.c. administration of 250 and 500 ng of LH-RH at 11.00 h on proestrus. Other doses were ineffective. The peptide (500 ng) was unable to induce pseudopregnancy in rats that received no cervicovaginal stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)